This invention is related to watering devices for automatically replenishing a liquid reservoir, such as in a battery, while simultaneously allowing battery gas build-up to be released, and more particularly to an automatic watering device having a housing mounted in the battery cell opening, and a float and valve pin suspended by a pair of internally mounted diaphragms for opening and closing a valve opening in the housing to either open or close communication between the source of water and the battery.
Many devices are known in the art for automatically maintaining the liquid level in an electric battery cell at an appropriate level. See, for example, U.S. Pat. No. 4,386,141 which issued May 31, 1983 to Evert C. Weidner and William B. Brecht. The problem with conventional automatic watering devices is that they sometimes employ a mechanical linkage which tends to become unreliable over a period of time, or they will not permit the gas build-up in the cell to be adequately released when the water delivery valve is closed.